Preliminary Study On Shield Structure And Ion Tolerance Of Brasenia Schreberi In Vivo

Brasenia schreberi J.F.Gmel.is an endangered perennial root herb.The application of anatomy and histochemistry to the study of Brasenia schreberi J.F.Gmel.mucilage hair structure and the permeability of ions is of certain significance to explain that water shield is endangered due to its intolerance to water pollution.Second,under the ionic stress,the changes of different dynamic and complex organosomal systems in living bodies are taken as the biological indicators in practice,and the characteristics of the outer mucilage hairs of Brasenia schreberi J.F.Gmel.can be used as the ecological indicators for endangered aquatic plants to adapt to the nutrient-poor environment.In this paper,the mucilage hair structure,histochemistry and ion permeability were studied.Sudan red 7B,berberine aniline blue,fluorescence stain,Hoechst 33342 and toluidine blue were used to observe the structural characteristics of Brasenia schreberi J.F.Gmel.under the stress of sodium chloride and alcohol solution.The results show:1.Brasenia schreberi J.F.Gmel.mucilage hairs are field of cells on the surface of the cuticle,including mucilage hair bubbles and glandular hairs.There are two saucers at the base,which produce both mucilage hair membrane and glandular hair membrane.Mucilage hair membrane with glycoproteins,and a variety of protoplasts.Discontinuous cuticle is surrounded by mucilage hair at mature stage.2.Ion permeability test prove Brasenia schreberi J.F.Gmel.mucilage hair membrane and glandular hair membrane absorb more ions at mature stage.But mucilage hair membrane and glandular hair membrane absorb more ions at aged stage.The membrane system of protoplasm in young glandular hair was smooth,the membrane system of protoplasm in mature hair was spot-like and spotty-like,and the membrane system of protoplasm in aged stage was decomposed,similar and fuzzy.Mucilage hair membranes and glandular hair membranes absorb more ions at mature stage to adapt to a nutrient-poor environment.Ion stress can accelerate the aged process of mucilage hairs in a short time.The permeability characteristics of water shield structure prove its sensitivity to water pollution and incorrect fertilization.3.The present research on B.schreberi mucilage hairs toxicity stressed by NaCl and ethanol gradient solutions acclerated senescense in short-term in vivo.The results show the young glandular hairs are more sensitive than mature hairs to treat with NaCl solutions that near half turn to senescense of young stage with 0.9% and mature stage with 1.8% at same time,and acclerate senescense that show as pillar-like,bubble-like and obscure as in aged stage hairs.The young glandular hairs are more tolerant than mature hairs to stress with ethanol solutions that near half turn to senescense of young stage with 3% and mature stage with 2% at same time,and speed up senility that show as pillar-like,bubble-like and obscure as in aged stage hairs.The mature hairs absorb ions maybe explain its more tolerant NaCl stressed in ionic permeability test,and the protoplast have dynamic complex organelle membrane system reveal young hairs more tolerant ethanol stress.We suggest the protoplast of mucilage hairs to establish a cell model for acute toxicity and moniter environment as biological indicator in practice.The destroyed water environment of B.schreberi is the directly reason for endangered,and put new way to protect endangered plants.